Psychotropic medications are prescribed to treat problem behavior (e.g., aggression and self-injury) of persons with intellectual and developmental disabilities (IDD). In the past, these medications were used to chemically restrain individuals with IDD and problem behavior, and this practice resulted in federal involvement to monitor medication use. Despite the changes that have been made in the use of psychotropic medications in the IDD population, a large percentage of the population is prescribed psychotropic medication with a majority of the individuals taking more than one medication (i.e., polypharmacy). This practice is concerning because individuals with IDD have been found to be more susceptible to experiencing adverse side effects (ASE). Furthermore, given difficulties with communication, they are less likely to report these ASEs. Although psychotropic medications are prescribed to treat disruptive behavior, there is ample evidence that demonstrates how behavior can also be treated by addressing environmental variables impacting behavior. Research has also demonstrated that psychotropic medication can exert differential effects on disruptive behavior impacting the circumstances in which behavior occurs. However, these studies have focused on single drug treatments, when in fact; polypharmacy is the reality of treatment. At present, it is unknown if, and if so how, polypharmacy and changes in polypharmacy regimens affect the relationship between behavior and the contingencies maintaining them. Even less is known regarding the role ASEs play in mediating this relationship. Further research needs to be conducted to extend what is known about the impact that polypharmacy regimens and their alterations have on problem behavior and reinforcement contingencies. Furthermore, research needs to determine what role, if any, ASEs play in impacting these behaviors and contingencies. The information yielded from this research could greatly contribute to the most efficacious behavioral and medicinal treatment for individuals with IDD. This line of research will enhance our understanding of how polypharmacy use impacts problem behavior of individuals with IDD, specifically how these medications may mediate the relationship between behavior and the environment in which it occurs. The purpose of the proposed study will be to investigate how polypharmacy use systematically affects problem behavior of persons with IDD. Direct observations will be conducted to monitor behavior throughout the study and analogue functional analyses (AFA) will be conducted when changes are made to polypharmacy regimens. Given previous research findings, we anticipate that changes in medication will produce changes in the results of AFAs. The findings of this research will confirm the importance and need for continued monitoring of behavior function, in addition to monitoring frequency and intensity, of problem behavior in order to determine the most efficacious treatment. Thus far, preliminary research results suggest that after psychotropic medication alterations are made, changes are indeed observed in behavior. The principle investigator has extensive experience, in both clinical and applied research settings, conducting AFAs to evaluate medication effects. Additionally, the principle investigator has ties to the community from which participants would be recruited and has ample students interested in conducting this type of research. Mission of NICHD. The proposed study fits well with NICHD's mission on several levels. First, completion of the specific aims should result in important insights for advancing clinical understanding of how changes in psychotropic medication regimens and potential medication ASEs can affect disruptive behaviors of individuals with IDD. Second, the proposed study is constructed to train undergraduate students to conduct scientific research to ensure the health, productivity, independence, and well-being of all people. PUBLIC HEALTH RELEVANCE: The relevance of this research to public health is that it will empirically validate a more robust method (i.e., continuous monitoring of behavior function) for determining the treatment effectiveness of psychotropic medication for problem behaviors such as aggression and self-injurious behavior in individuals with intellectual disabilities (ID). These behaviors often serve as a barrier for individuals with ID to living in community (versus institutional) settings. Furthermore, the number and combination of medications used to treat these behaviors can produce adverse side effects that can compromise one's quality of life. Based on the findings of this research, the likelihood that psychotropic medication will be used with greater efficacy and in combination with more appropriate behavioral interventions may increase. Furthermore, the outcomes of this research may provide psychiatrists with a new way of monitoring medication effectiveness and ultimately impact how medication is prescribed.